Unlocked an At&t SGS3 for use on Tmo - AT&T, Rogers, Bell, Telus Samsung Galaxy S III

Hey guy I just unlocked an old SGS3 for AT&T SGH-I747. Now i plan on giving the phone to my mom for her to use since her current phone is a POS... how would i go about getting tmobile firmware on it for her without bricking. I know i have to root first and then Recovery then Rom, but is it safe and stable to run TMO rom on the att model of the S3. I just want to make sure that i go about this the rite way.
Thanks in advance

Will she be using T-Mobile data? The i747 does not natively support aws frequencies so that may be a problem. Voice calls would probably work.
You can't flash the t999 modem and bootloader to the i747 so forget about flashing a T-Mobile rom to i747.

Pray tell: How did you Un-Lock it?
I haven't been able to get past the debug screen?
Any info is appreciated, Thanks!
JosephJ85 said:
Hey guy I just unlocked an old SGS3 for AT&T SGH-I747. Now i plan on giving the phone to my mom for her to use since her current phone is a POS... how would i go about getting tmobile firmware on it for her without bricking. I know i have to root first and then Recovery then Rom, but is it safe and stable to run TMO rom on the att model of the S3. I just want to make sure that i go about this the rite way.
Thanks in advance
Click to expand...
Click to collapse

Related

[Q] At&t to T-Mobile

Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!
bradhoschar said:
Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!
Click to expand...
Click to collapse
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.
Okaham said:
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.
Click to expand...
Click to collapse
You got that right.
:thumbup:
Sent while sleeping in chair.
Okaham said:
since your device is still an AT&T branded Galaxy S III (SGH-i747), you must keep with ROMs designed for that phone. flashing T-Mobile branded Galaxy S III (SGH-T999) ROMs will brick your device, same thing goes for flashing modems.
just because your SIM and Carrier is now T-Mobile, doesn't mean your phone is.
Click to expand...
Click to collapse
Wrong. Flashing an rom meant for the AT&T variant of the S3 on a T-Mobile variant S3 and vice versa will not brick the device. APN setting may get messed up and you have to enter them manually but it will not brick the device. Flashing a ROM for the international S3 on a U.S. variant of the S3 and vice versa will brick the device.
I wouldn't recommend flashing modems between the variants of S3s, that may or may not brick the device but wouldn't try it.
|When Emotion Goes up, Logic Goes Down|
---------- Post added at 03:40 PM ---------- Previous post was at 03:36 PM ----------
bradhoschar said:
Here's the issue. I purchased the At&t s3 (SGH-I747) last year. Long story short, I wanted to go to T-Mobile prepaid with the same phone.
I purchased the SIM activation kit for $10, popped my SIM in and it worked!
Before I put the SIM in it though, I paid for an unlock code. I still have the code.
No 'Network Unlock' screen.
No prompt for my unlock code.
I am getting H+ speeds with the at&t s3 on T-Mobile prepaid without doing ANYTHING.
My question is:
Why cant I get to the unlock screen? I have tried to dial "#7465625*638*# for the prompt to popup and NOTHING.
Can someone tell me...
1. Can I flash a T-mobile rom to this phone? (every time i try I get a build.prop error, even after changing the model to the T999 and all that jazz),
so I can't install a T-Mo rom?
2. Do I have to flash a modem/radio or anything else like that?
3. Or, should I just continue to flash At&t Roms with the t-mo prepaid sim?
I have searched for a while now, and noone has my problem. I never expected to just switch sim's and it would work, so ANY help would be appreciated.
Thanks!
Click to expand...
Click to collapse
If you want to unlock the S3 (you must be stock to do this, stocked rooted may work, but I'm not sure):
Just dial the following keys *#197328640#
Main Menu
[1] UMTS
[1] Debug Screen
[8] Phone Control
[6] Network Lock
Options [3]Perso SHA256 OFF
(after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in
[6] Network Lock then choose
[4] NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone
|When Emotion Goes up, Logic Goes Down|
Hello.
If you have signal then why are you trying to use the code? It is unlocked already!
im not an expert but this is what i know from reading a lot:
1.- I installed a t-mobile (t999) rom modified to work in a att s3 (i747), i think you can flash a any rom from the t999 section (i am not sure about this)
2.- Do NOT try to install a modem from t-mobile or you will hard brick your phone.
3.- Thats a good idea, do it and let me know if it works.
I used this files to convert an i747 to a t999 http://forum.xda-developers.com/showthread.php?t=1771021&page=25 (read from post #246) so now i use customs roms for the t999 i did it because where i live do not have good signal, was stuck at edge and with those files now i have 3g signal.
Btw, i am in the $30 prepaid t mo plan.
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re: Hmm
xmanberserker said:
Hello.
If you have signal then why are you trying to use the code? It is unlocked already!
im not an expert but this is what i know from reading a lot:
1.- I installed a t-mobile (t999) rom modified to work in a att s3 (i747), i think you can flash a any rom from the t999 section (i am not sure about this)
2.- Do NOT try to install a modem from t-mobile or you will hard brick your phone.
3.- Thats a good idea, do it and let me know if it works.
I used this files to convert an i747 to a t999 http://forum.xda-developers.com/show...771021&page=25 (read from post #246) so now i use customs roms for the t999 i did it because where i live do not have good signal, was stuck at edge and with those files now i have 3g signal.
Btw, i am in the $30 prepaid t mo plan.
Click to expand...
Click to collapse
#1: If you have a Unlocked AT&T I747 Galaxy S3 you don't need any files to convert it to work on any T999 Tmobile roms.
#2: You can use any T999 Tmobile custom roms as long as you have an Unlocked & Rooted AT&T Galaxy S3 I747 Phone.
#3: There is no such thing as installing or flashing any files which would would change the frequency for 3G on a I747 phone.
#4: Your link is dead... LOL
#4: Your link is dead... LOL[/QUOTE]
http://forum.xda-developers.com/showthread.php?t=1771021&page=25 Fixed
Misterjunky said:
#1: If you have a Unlocked AT&T I747 Galaxy S3 you don't need any files to convert it to work on any T999 Tmobile roms.
#2: You can use any T999 Tmobile custom roms as long as you have an Unlocked & Rooted AT&T Galaxy S3 I747 Phone.
#3: There is no such thing as installing or flashing any files which would would change the frequency for 3G on a I747 phone.
#4: Your link is dead... LOL
Click to expand...
Click to collapse
That is not true. Before following these instructions ( http://forum.xda-developers.com/showthread.php?t=1771021&page=25 ) I could NOT install any t-mo rom as CWM verifies the make/model before installing the rom.
Hence, me having the 'installation cannot continue' build.prop=d2att.
So, now AFTER flashing the 4 files, I was able to install 3 different T-Mobile ROMS. XTREMEPERIA ( http://forum.xda-developers.com/showthread.php?t=2199018 ) was the only one that is giving me 4G. I know, I know, its all in the APN settings, but this is the only one that gave me truly 4G speeds with a T-Mo sim.
re: 3G/4G
bradhoschar said:
That is not true. Before following these instructions ( http://forum.xda-developers.com/showthread.php?t=1771021&page=25 ) I could NOT install any t-mo rom as CWM verifies the make/model before installing the rom.
Hence, me having the 'installation cannot continue' build.prop=d2att.
So, now AFTER flashing the 4 files, I was able to install 3 different T-Mobile ROMS. XTREMEPERIA ( http://forum.xda-developers.com/showthread.php?t=2199018 ) was the only one that is giving me 4G. I know, I know, its all in the APN settings, but this is the only one that gave me truly 4G speeds with a T-Mo sim.
Click to expand...
Click to collapse
You are right, clockworkmod (Rom Manager) does verify, however if you select
and flash the Tmobile T999 recovery image when flashing clockworkmod recovery
all is fine.
Another thing, if you have a unlocked i747 and flash any Tmobile cwm zip file rom as
soon as it reboots and you check the network in the phones settings it will display
"T-Mobile US" and will work properly without the need of any other files or conversions.
However the Unlocked I747 will never work with Tmobile's 3G or 4G networks.
Misterjunky said:
You are right, clockworkmod (Rom Manager) does verify, however if you select
and flash the Tmobile T999 recovery image when flashing clockworkmod recovery
all is fine.
Another thing, if you have a unlocked i747 and flash any Tmobile cwm zip file rom as
soon as it reboots and you check the network in the phones settings it will display
"T-Mobile US" and will work properly without the need of any other files or conversions.
However the Unlocked I747 will never work with Tmobile's 3G or 4G networks.
Click to expand...
Click to collapse
Ahh...good tip about CWM
I currently have 4g on my unlocked S3 from at&t currently on T-Mobile.
And, when I was on stock, I had 3g
re: Tmobile Network.
bradhoschar said:
Ahh...good tip about CWM
I currently have 4g on my unlocked S3 from at&t currently on T-Mobile.
And, when I was on stock, I had 3g
Click to expand...
Click to collapse
Yes but when you were on stock you were on the AT&T network not Tmobile.
Misterjunky said:
Yes but when you were on stock you were on the AT&T network not Tmobile.
Click to expand...
Click to collapse
No, that is incorrect. With the 4 files I flashed, I was on T-Mobile network. It was a T-Mobile ROM, T-Mobile sim, and T-Mobile radio.
bradhoschar said:
No, that is incorrect. With the 4 files I flashed, I was on T-Mobile network. It was a T-Mobile ROM, T-Mobile sim, and T-Mobile radio.
Click to expand...
Click to collapse
Quit saying you are using a T-Mobile radio before you help someone brick their phone. The radio files are NOT interchangeable between ANY of the US variants!
EtherealRemnant said:
Quit saying you are using a T-Mobile radio before you help someone brick their phone. The radio files are NOT interchangeable between ANY of the US variants!
Click to expand...
Click to collapse
Oh, my bad. I thought 'modem' and 'radio' were the same thing.
THEY ARE!!!!
Notice in the picture how under the 'phone' tab, it says MODEM.
Yes, I flashed all 4, and now have a t-mobile setup on an at&t s3.
bradhoschar said:
Oh, my bad. I thought 'modem' and 'radio' were the same thing.
THEY ARE!!!!
Notice in the picture how under the 'phone' tab, it says MODEM.
Yes, I flashed all 4, and now have a t-mobile setup on an at&t s3.
Click to expand...
Click to collapse
You need to specify that you are using an engineering image that T-Mobile used on the 747 before the T-999 was available to test the device. In general if you flash a T-Mobile radio image to a 747, you risk losing calls and data at minimum and a hard brick at worst. It is imperative to make sure to point out that it only works with THAT engineering set.
EtherealRemnant said:
You need to specify that you are using an engineering image that T-Mobile used on the 747 before the T-999 was available to test the device. In general if you flash a T-Mobile radio image to a 747, you risk losing calls and data at minimum and a hard brick at worst. It is imperative to make sure to point out that it only works with THAT engineering set.
Click to expand...
Click to collapse
Ahh...gotcha. Thats what it states in THAT OP, I just thought that once that build was on the phone, from that point on, any T-Mo anything would work. I did have the watermark on my wallpaper, but everything else said 't-mobile'.
But, yes in general, if you flash TMO onto AT&T, there be dragons.
Thanks all, and happy flashing!
Even with that configuration, the only thing T-Mobile you can flash is recovery and custom ROMs. A T-999 baseband or boot loader could very well cause a brick. Its a dangerous hack because it has everyone confused. For all intents and purposes, it is 747 software with T-Mobile's AWS capability. In fact it doesn't even seem to have DC-HSPA, only HSPA+ (21mbps versus 42). It has the benefit of supporting T-Mo LTE though.
Awesome
EtherealRemnant said:
Even with that configuration, the only thing T-Mobile you can flash is recovery and custom ROMs. A T-999 baseband or boot loader could very well cause a brick. Its a dangerous hack because it has everyone confused. For all intents and purposes, it is 747 software with T-Mobile's AWS capability. In fact it doesn't even seem to have DC-HSPA, only HSPA+ (21mbps versus 42). It has the benefit of supporting T-Mo LTE though.
Click to expand...
Click to collapse
Very good to know! Thanks for the info. Perhaps when T-Mo refarms their LTE, I won't have to do much to this beastly phone!
Thanks all!
:good:
bradhoschar said:
Very good to know! Thanks for the info. Perhaps when T-Mo refarms their LTE, I won't have to do much to this beastly phone!
Thanks all!
:good:
Click to expand...
Click to collapse
It doesn't make sense for T-Mobile to refarm their LTE. The 1700 AWS band is the most efficient spectrum they currently own and the AWS spectrum is going to be the most compatible across LTE networks. T-Mobile has pretty much no chance of ever getting the 700MHz that at&t and Verizon are using.

ATT SGH -i747 Unlocked on TMO no Sim error

I am confused and looking for some help. I have a SGH-i747 ATT S3 which I rooted before when I was on ATT. I currently unlocked it and then decided to change my rom. Being that I was not on TMO network I downloaded a TMO rom however once it was done I got a no sim error. In this situation is best to continue using ATT roms? I am going to unroot back to ATT and see if that clears the problem. What is recommended in my situation?
marqis said:
I am confused and looking for some help. I have a SGH-i747 ATT S3 which I rooted before when I was on ATT. I currently unlocked it and then decided to change my rom. Being that I was not on TMO network I downloaded a TMO rom however once it was done I got a no sim error. In this situation is best to continue using ATT roms? I am going to unroot back to ATT and see if that clears the problem. What is recommended in my situation?
Click to expand...
Click to collapse
I unrooted it and flashed the stock ATT rom back to it and it came back to life thank goodness. just an FYI.

[Q] Reflash unlocked AT&T GS3 (i747) to Tmobile (t999)?

I have an AT&T Galaxy S3 (Model SGH-i747) that I have unlocked and am using on Tmobile. Since it was originally an AT&T device, am I able to use Odin and simply replace the ROM with the Tmobile version (t999 I believe)? The phone is totally stock with the exception of being unlocked with a code from AT&T. It is running Android 4.1.2 Kernel Version 3.0.31-1300972. I downloaded a ROM for the Tmobile t999 with Android 4.3 and when I tried to install it Odin gave me an error: Secure check fail sbl2. I really don't like the AT&T boot screen and AT&T bloatware, and I'd like to run the factory Tmobile setup. Is this doable or are the 2 models of Galaxy S3 different enough to prevent it?
Flashing a stock T999 ROM will also try to flash a bootloader and modem that are not compatible with your i747 and may hard brick your phone.
Thank you, I appreciate the help. Do you know what options are available if I want to get rid of the AT&T boot screen and bloatware (Specifically the AT&T contacts book) while maintaining all the functionality of the device? I have been searching around on this site and google and I've been having a hard time finding information specific to this situation.
You could try a custom ROM but before flashing anything, it's a good idea to verify your bootloader and modem version.
If you are running an old bootloader and modem, you'll have to decide if you want to upgrade to use the latest custom ROMs or stick with your current bootloader and modem.

[Q] Sim unlock on custom ROM. Tmobile support not being helpful.

So I'm currently in Europe and I will be here for 2 more months and I would like to unlock my phone because $4.19 a minute is ridiculous. However tmobile support is being, let's say very smart. The first representative said "just visit you're nearest tmobile store and we'll help you out there." After I had already told them I was in a country without tmobile. So I was wondering if there was any way to do this for free? I really don't want to have to spend any more money right now. I'm currently running liquidsmooth lollipops latest build. And I really don't want to have to revert to stock because I currently have Internet speeds of 85kb/s and that would take ages to download and then reset up my phone. All help is greatly appreciated.
You cannot. Need TouchWiz
serio22 said:
You cannot. Need TouchWiz
Click to expand...
Click to collapse
Which version should i downgrade to, and could you give me a like to a method of unlocking it?
Before flashing any TW ROMs via Odin, confirm the bootloader and modem on your phone.
I'm not sure but if the T999 is like the i747 (ATT s3 version), you cannot downgrade the bootloader from 4.3 to a lower version. Doing so may brick the phone.
If you are on a 4.1.1 or 4.1.2 bootloader, you should be able to downgrade to stock 4.1.1 and you may be able to unlock for free using this method: http://forum.xda-developers.com/showthread.php?t=2014982
If you cannot downgrade to stock 4.1.1, you'll need to buy an unlock code and enter it using a stock Samsung dialler.

Is "SM-N920T" Firmware ok, on a "SM-N920A" Phone ?

Hey guys, just had a question. I have a SM-N920A phone. Will it brick my phone if i flash it through ODIN with "N920TUVS5ERC1" thats meant for the SM-N920T Tmobile Note 5. I hate the AT&T bloatware and would like to have the Tmobile Version of the Note 5. Just not sure if the Tmobile Firmware will brick my AT&T phone. Will it work ?
Thanks guys
euserdb said:
Hey guys, just had a question. I have a SM-N920A phone. Will it brick my phone if i flash it through ODIN with "N920TUVS5ERC1" thats meant for the SM-N920T Tmobile Note 5. I hate the AT&T bloatware and would like to have the Tmobile Version of the Note 5. Just not sure if the Tmobile Firmware will brick my AT&T phone. Will it work ?
Thanks guys
Click to expand...
Click to collapse
It will not work. Locked bootloader for AT&T signed software. Maybe it will flash but virtually no chance it will boot. Even if it did boot, there most likely won't be any cell service.
Oh ok, i see. Yeah you problaly need the same basebands or something for the firmware to work. Well, thanks i appreciate it
If you did get it to boot, using an unlocked modem firmware would be the trick to getting cell service again.
Please, please, don't flame me if I bumped this as it's been inactive for a while... but I wanted to know if there was any progress with this?
I also have a Note 5 N920A that I'd basically like to make into a N920T. I understand that the bootloader is unlocked, but where keys exist, is there not a way to unlock it? I've been out of the development community for quite a while and will catch up a little but I hope someone would have time enough to explain a little.
I unlocked this phone and use it on T-mobile but it doesn't get service where the almost identical T-mobile version of the phone does...
What if I left the bootloader alone and just wanted to take full advantage of T-Mobile's LTE bands? Can I just flash an unlocked modem from _____?
What're the workaround options for this?
Please and thanks in advance
I've been searching for the answer to the same, if not similar, question. I'm trying to find a way or work-around to get T-mobile wifi calling to work.

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